Create separation between private and public repos for alma9

CC7 has the separation yum.repod.d and yum.repos.d-public. One of them is for internal use (based on the cta-ci-others repo that we maintain internally). The other is for the public as we cannot distribute the oracle rpms.

The alma9 setup does not have such a separation and the ci now copies all the repos even though this should not be necessary. We need a similar distinction in alma9 as well. This should also resolve the issue with the oracle client (see #747 (closed)).